Conventionally, in a silo for storing particle/bulk material, such as coals, coke, or limestone, a discharge device is provided at a cone portion formed at a lower portion of the storage silo, and the particle/bulk material are discharged by the discharge device to a belt conveyor provided at a lower side of the storage silo. The particle/bulk material discharged to the belt conveyor is conveyed by the belt conveyor to a predetermined place outside the storage silo.
For example, in a large-scale storage silo in a thermal power facility, the cone portion is provided to extend from one end portion to the other end portion of the storage silo, a groove through which the particle/bulk material in the storage silo are discharged is formed at a lower portion of the cone portion, and a movable discharge device configured to move along the groove is provided to discharge the particle/bulk material. The belt conveyor is provided along and under the groove, and the particle/bulk material are conveyed by the belt conveyor to the predetermined place.
One example of such a movable discharge device is configured such that: stored substances at a lower portion of the storage silo are raked by a blade curved in an arch shape and configured to rotate in a horizontal plane; and the stored substances are discharged through the groove to the belt conveyor. The movable discharge device moves in the storage silo to discharge the stored substances. With this, a significant storage difference (nonuniform height) of the stored substances in the storage silo is not generated.
One example of this type of conventional art is that as shown in FIG. 11, a plurality of chutes 107 and a plurality of cone portions 102 are provided at a bottom of a large-diameter reserve silo 101, and sweep-out devices 104 are configured to respectively travel along grooves 103 formed at lower ends of the chutes 107. Each of the sweep-out devices 104 travels along the groove 103 to sweep out particle/bulk material 106 from an inside of the silo 101 to a conveyor 105 provided under the chute 107 (see PTL 1, for example).
Another conventional art is that in order that reserved substances in a reserve silo can be supplied to a sweep-out device without causing clogging, a hopper at a lower end of the silo is formed to have an oval shape, a flat bottom plate having an oval shape is provided at a lower end opening portion of the hopper to once receive the reserved substances in the silo, and the reserved substances on the flat bottom plate in the silo are swept down by the rotation of a horizontal rotating arm through a sweep-out opening portion of the flat bottom plate to the sweep-out device located at a lower side (see PTL 2, for example).